Metallic iron (Fe0) within lunar soil grains can affect their visual and near-infrared spectra, adhesion, biological toxicity, and electro-static migration characteristics. The Fe0 particle therefore is an important component of lunar soil. This study devised a high -temperature carbothermic reduction method for preparing Fe0 via graphite reduction of Chinese Lunar Regolith Simulant (CLRS-2) in an argon atmosphere, which is similar to the Fe0 in the agglutinitic glass of lunar samples. The X-ray diffraction and electron micro-scopy data show that the mixture of lunar soil simulants and graphite heated at high temperature rapidly quenched to form a glassy phase with dispersed Fe0 particles, the microstructure of which is consistent with the a-Fe (bcc) in lunar soil. This paper also discusses the main influencing factors for preparing Fe0, such as the ratio of raw materials, heating temperature, and holding time. The optimal experimental conditions are a graphite-to-CLRS-2 mass ratio of 1.0: 27.0 (Fe/C = 2.0: 2.6), reduction temperature of-1600 degrees C, and holding time of-4 h, which produce single-phase a-Fe with an average particle size of-180 +/- 10 nm and no residual impurities (e.g., graphite). (c) 2022 COSPAR. Published by Elsevier B.V. All rights reserved.

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